Many storage containers, such as large truck trailers, for example, include sidewalls made from composite panels. Illustratively, such composite panels may include a plastic core member sandwiched between thin metal skins. The composite panels are thereafter joined together to create the trailer sidewall. For example, DURAPLATE® composite panels provided by Wabash National Corporation of Lafayette, Ind. are constructed of a high-density polyethylene plastic core bonded between two high-strength steel skins.